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29th of March 2016

Sensitivity of an ASKAP PAF on the Parkes 64-m antenna

by Aaron Chippendale and Xinping Deng (CASS)

We have measured the sensitivity of an ASKAP phased array feed (PAF) on the Parkes 64 m radio telescope. The above plot shows the beamformed system noise-temperature-over-efficiency (Tsys/eta) of the ASKAP Mk. II PAF now installed at the focus of the Parkes 64 m antenna. The line colours show the three ASKAP digital receiver sampling bands. We have not yet measured from 1.1 GHz to 1.2 GHz, but other gaps in the plotted results are due to radio-frequency interference.
This preliminary result is for a boresight beam made with maximum signal-to-noise ratio weights. We used the radio galaxy Virgo A (M87) to calibrate the beamforming weights and to measure the beam sensitivity. The PAF we are testing has modifications to cope with the stronger radio-frequency interference seen at sites like Parkes that are not as remote as the ASKAP site. This work forms part of CSIRO's collaboration with the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany. They will install this PAF on the 100 m antenna at Effelsberg.